When air is heated up the molecules spread out and move faster, so heat rises because it is less dense than the cooler air around it.
Newton proved that the force that causes, for example, an apple to fall toward the ground is the same force that causes the moon to fall around, or orbit, the Earth. This universal force also acts between the Earth and the Sun, or any other star and its satellites. Each attracts the other.
The unit of measurement in an ecological footprint is the global hectare.
D would occur more rapidly.
